Population structure of the traditionally exploited holothurian Holothuria tubulosa in the south Aegean Sea

Abstract

Population structure of the traditionally exploited holothurian, Holothuria tubulosa, was studied in the south Aegean Sea for two consecutive years. Conspicuous populations of the species were detected at four of the eight surveyed islands, with a mean abundance, estimated through fishing effort, at 75 +/- 101 ind.h(-1) dive. Size-frequency distributions were unimodal at each surveyed island that hosted conspicuous populations. Holothurians mean size and gonad index had smaller values at Pserimos Island, while the relevant temporal differences were not significant. The oligotrophic status of the Dodecanese complex combined with the effect of uncontrolled fishery may explain the observed results.